Diesel Data: Automotive Repair

Tachometer Malfunction








METER / GAUGE / DISPLAY: METER / GAUGE SYSTEM: Tachometer Malfunction

Tachometer Malfunction

DESCRIPTION

In this circuit, the meter CPU receives engine revolution signals from the ECM using the CAN communication line (CAN No. 1 Bus). The meter CPU displays engine revolution data that is calculated based on the data received from the ECM.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM
(a) Check if CAN communication DTC is output Diagnosis System.
Result:






B -- GO TO CAN COMMUNICATION SYSTEM
A -- Continue to next step.
2. PERFORM ACTIVE TEST USING TECHSTREAM (TACHOMETER OPERATION)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Combination Meter / Active Test.
(e) Check the operation by referring to the values in the table below.

Combination Meter





OK:
Tachometer indication is normal.
NG -- REPLACE COMBINATION METER
OK -- Continue to next step.
3. READ VALUE USING TECHSTREAM (ENGINE RPM)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch on.
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Combination Meter / Data List.
(e) Check the values by referring to the values in the table below.

Combination Meter





Result:






B -- READ VALUE USING TECHSTREAM (ENGINE SPEED)
A -- REPLACE COMBINATION METER
4. READ VALUE USING TECHSTREAM (ENGINE SPEED)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List.
(e) Check the values by referring to the table below.

Engine and ECT





OK:
Engine speed displayed on the Techstream is almost the same as the tachometer indication.
Result:






C -- GO TO SFI SYSTEM (for 2ZR-FE)
B -- GO TO SFI SYSTEM (for 2AZ-FE)
A -- Continue to next step.
5. REPLACE ECM
(a) Replace the ECM with a new or a known good one Removal for 2AZ-FE, Removal for 2ZR-FE).
OK:
The operation of the tachometer returns to normal.
NG -- REPLACE COMBINATION METER
OK -- END